Embodiments of the present disclosure generally relate to organic photodetectors. More particularly, embodiments of the present disclosure relate to methods for packaging organic photodetectors such as organic x-ray detectors.
Digital x-ray detectors fabricated with continuous photodiodes have potential applications for low cost digital radiography as well as for rugged, light-weight and portable detectors. These x-ray detectors generally include an imager device having an organic photodiode, and a scintillator that converts x-ray to visible light disposed on top of the organic photodiode. Such organic x-ray detectors usually have an increased fill factor and potentially higher quantum efficiency.
One of the technical challenges for organic x-ray detectors is reliability. Organic x-ray detectors are often subject to performance degradation upon exposure to oxygen and/or moisture because of increased dark current in the organic photodiodes and subsequently increased number of defect pixels. Adding barrier films directly atop the organic photodiode may be an effective way to improve stability of the organic photodiode layers and performance of the organic x-ray detectors. However, it may be difficult to achieve high quality (e.g., pinhole-free) thin barrier films in a practical and cost-effective manner.
Further, the organic x-ray detectors may employ an encapsulation cover such as a glass sheet, a metal film or plate. The encapsulation cover may be hermetically sealed to isolate the organic x-ray detector from the atmospheric oxygen and/or moisture. Further, this encapsulation and sealing may be performed inside an inert environment such as a glovebox filled with nitrogen or an inert gas to avoid any exposure to the atmospheric oxygen and/or moisture. However, it may be desirable to perform the encapsulation and sealing in the ambient environment for process yield and low-cost manufacturing, especially for large area organic x-ray detectors. This may lead to trapped air inside the encapsulation cover in the packaged detectors. The trapped air may attack the organic photodiode through the pinholes in the barrier film degrade the performance of the organic x-ray detectors.
Therefore, there is a need for improved ways for packaging organic photodetectors, for example organic x-ray detectors for forming detector packages.